package lesson.login;

import lesson.base.BaseServlet;
import lesson.permission.Uncheck;
import lesson.user.User;
import lesson.user.UserService;

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Objects;
import java.util.Random;

@WebServlet("/login/*")
public class LoginServlet extends BaseServlet {

    private UserService userService = new UserService();



    /**
     * 登录页面
     * @throws ServletException
     * @throws IOException
     */
    @Uncheck
    public void index()  throws ServletException, IOException{

        getRequest().getRequestDispatcher("/index.jsp").forward(getRequest() , getResponse());
    }
    /**
     * 登录校验
     * @throws ServletException
     * @throws IOException
     */
    @Uncheck
    public void check(String name, String pwd, String code, Integer role)  throws ServletException, IOException{

        System.out.println("role:" + role + "name:" + name + "pwd:" + pwd+"code:"+code);
        String sessionCode = (String) getRequest().getSession().getAttribute("verifyCode");
        if (sessionCode != null) {
            sessionCode = sessionCode.toLowerCase();
        }
        if (code != null) {
            code = code.toLowerCase();
        }
        if (Objects.equals(sessionCode, code) == false) {
            getRequest().getSession().setAttribute("verifyCode",new Random().nextInt(2000));
            writeJSON(false, "验证码填写错误");
            return;
        }



        User user = userService.checkLogin(name, pwd, role);

        if (user == null) {
            writeJSON(false, "登录失败");
        } else {
            writeJSON(true, "登录成功");

        }
    }

    /**
     * 登录验证码
     * @throws ServletException
     * @throws IOException
     */
    @Uncheck
    public void code()  throws ServletException, IOException{
        try {

            int width=200;

            int height=69;

            BufferedImage verifyImg=new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);

            //生成对应宽高的初始图片

            String randomText = VerifyCode.drawRandomText(width,height,verifyImg);

            getRequest().getSession().setAttribute("verifyCode", randomText);
            //单独的一个类方法，出于代码复用考虑，进行了封装。

            //功能是生成验证码字符并加上噪点，干扰线，返回值为验证码字符


            getResponse().setContentType("image/png");//必须设置响应内容类型为图片，否则前台不识别

            OutputStream os = getResponse().getOutputStream(); //获取文件输出流

            ImageIO.write(verifyImg,"png",os);//输出图片流

            os.flush();

            os.close();//关闭流

        } catch (IOException e) {


            e.printStackTrace();

        }
    }


    private static class VerifyCode {

        public static  String drawRandomText(int width,int height,BufferedImage verifyImg) {
            Graphics2D graphics = (Graphics2D)verifyImg.getGraphics();
            graphics.setColor(Color.WHITE);//设置画笔颜色-验证码背景色
            graphics.fillRect(0, 0, width, height);//填充背景
            graphics.setFont(new Font("微软雅黑", Font.BOLD, 40));
            //数字和字母的组合
            String baseNumLetter=  "123456789abcdefghijklmnopqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ";

            StringBuffer sBuffer = new StringBuffer();
            int x = 10;  //旋转原点的 x 坐标
            String ch = "";
            Random random = new Random();
            for(int i = 0;i < 4;i++){
                graphics.setColor(getRandomColor());
                //设置字体旋转角度
                int degree = random.nextInt() % 30;  //角度小于30度
                int dot = random.nextInt(baseNumLetter.length());
                ch = baseNumLetter.charAt(dot) + "";
                sBuffer.append(ch);
                //正向旋转
                graphics.rotate(degree * Math.PI / 180, x, 45);
                graphics.drawString(ch, x, 45);
                //反向旋转
                graphics.rotate(-degree * Math.PI / 180, x, 45);
                x += 48;
            }
            //画干扰线
            for (int i = 0; i <6; i++) {
                // 设置随机颜色
                graphics.setColor(getRandomColor());
                // 随机画线
                graphics.drawLine(random.nextInt(width), random.nextInt(height),
                        random.nextInt(width), random.nextInt(height));
            }
            //添加噪点
            for(int i=0;i<30;i++){
                int x1 = random.nextInt(width);
                int y1 = random.nextInt(height);
                graphics.setColor(getRandomColor());
                graphics.fillRect(x1, y1, 2,2);
            }
            return sBuffer.toString();
        }
        /**
         * 随机取色

         */
        private static Color getRandomColor() {
            Random ran = new Random();
            Color color = new Color(ran.nextInt(256),
                    ran.nextInt(256), ran.nextInt(256));
            return color;
        }
    }
}
